This is where the harmonic balancer comes in. The circular device, made of rubber and metal, is bolted at the front end of the crankshaft to help absorb vibrations. It's usually connected to the crank pulley, which drives accessories like the air conditioner.
Additional costs: Ground water wells can also be tested for radon, then, if needed, can get a water radon mitigation system installed. Installing a water radon mitigation system runs from $1,000-$4,500, and maintenance runs $0 to $150 annually.
A quality radon reduction (mitigation) system is often able to reduce the annual average radon level to below 2 pCi/L. In general, costs can range from approximately $800-$2500, with the average reduction system costing approximately $1500.